Prohydrojasmon treatment reduces root-knot nematode penetration in tomato

Root-knot nematodes (RKN) are well-known plant parasites that seriously damage crops. Meloidogyne incognita, the most prevalent species, infects many globally important crops, including tomato (Solanum lycopersicum L.). Some jasmonic acid (JA) derivatives enhance tolerance against RKN, but the synthetic JA derivative 'prohydrojasmon' (PDJ) has not been thoroughly studied. This study investigated PDJ's influence on M. incognita infection in tomato, focusing on second-stage juveniles (J2) penetration.

We used Jasmomate® SL, a commercial plant growth regulator, for the PDJ treatment. PDJ application to tomato significantly reduced M. incognita penetration, with root application being more effective than shoot application. In a soaking test, PDJ did not exhibit nematicidal activity against M. incognita J2 even at the highest concentration in this study. An inoculation experiment with M. incognita soaked in PDJ solution showed no significant difference among treatments. PDJ application also reduced penetration from a Mi-1-virulent isolate of M. incognita and two other Meloidogyne species.

This study suggests that PDJ treatment in tomato suppresses RKN infection through inhibitory mechanisms against J2 penetration, possibly by activating JA-related basal defense in the host plant. Future research should demonstrate PDJ's practical effectiveness and clarify the detailed mechanisms affecting RKN infection, positioning PDJ as a new eco-friendly tool for RKN control as a plant activator. © 2025 Society of Chemical Industry.